AnkitaSinghal

of(1, 2, 3).pipe(exhaustMap((x) => interval(2000)
.pipe(take(3),tap((t) => console.log(x, t)))) )
.subscribe((d) => console.log('GOT ', d));

// Merge Map : 1 0, 2 0, 3 0, 1 1, 2 1, 3 1, 1 2, 2 2, 3 2
// switchMap: 3 0, 3 1, 3 2
// ConcatMap: 1 0, 1 1, 1 2, 2 0, 2 1, 2 2, 3 0, 3 1, 3 2, 
// exhaustMap: 1 0, 1 1, 1 2

AnkitaSinghal

// Fork join - subscribe to several parallel observables, wait for all to complete and do something with the result
// https://medium.com/better-programming/rxjs-forkjoin-never-use-array-indexes-in-subscribe-1f4005582ae8 
forkJoin(
  this.http.get('some/api/welcomeMessage'),
  language$,
  dateRange$
  // Use tab to handle data processing for each observable separately
    .pipe(tap(([startDate, endDate]) => { 
      this.startDate = startDate;
      this.endDate = endDate;